John fielding



(No Model.) 2 sheets-sheet i..

- J. EIELDING. f

, VALVE GEAR EOE DUPLEX ENGINES.

No. 334,576. jPatented Jan. 19, 1886.

l l l N. PEYERS, Phmo-Umugmplmr. Washington, D. C

(No Model.) 2 Sheets-Sheet 2.

J. FIELDING. VALVE GEAE EOEEUPLEX ENGINES.

No.334',576. PatentedJan. 19, 1886.

v UNITED STATES JOHN FIELDING, OF GLOUCESTER, COUNTY OF GLOUCESTER, ENGLAND.

PATENT OFFICE.

VALVE-GEAR BOR DUPLEX ENGINES.

SPECIFICATION forming part of Letters Patent No. 334,576, dated January 19, 1886.

Application filed September 29,1885. Serial No. 178,561. (No model.) Patented in England April 2, 1885, No 4,199.

To aZZ whom, it may concern-.-

Be it known that I, JOHN FIELDING, a citizen of England, residing at Gloucester, England, have invented Valve-Gear for Duplex Engines, (for which I have obtained Letters Patent in Great Britain, dated vApril 2, 1885, No. 4,199,) of which the following is a speciiication.

Directacting pumping-engines wherein the steam-piston is rigidly connected to the pump-piston are sometimes made in duplex form-that is to say, two such engines are placed side by side, with valves and gear so arranged that the piston of each cylinder as it moves to and fro works the valves for the supply and exhaust of the other cylinder. My invention relates to engines of this kind; and it consists in the novel mechanism hereinafter described and claimed for imparting to a single slide-valve two movements, the one a reciprocation in a right line and the other a transverse reciprocation.

In the accompanying drawings, illustrating my invention, Figure lis aside view, and Fig. 1a is a plan, of the duplex engine, showing the position of the one valve-box for the two cylinders and the connections for working the valve from the cross-heads of the two pistonrods. The other gures, which are drawn to an enlarged scale, are Fig. 2, a longitudinal section, and Fig. 3 a plan, of the slide-valve and gear, and Fig. 4 a transverse section on K X of Fig. 3. Fig. Llisa plan showing amodiiied form of the ports; and Fig. 5 is a plan, and Fig. 6 a transverse section, of the slide-valve, as modified to suit these ports.

The cross-heads of the two piston-rods are linked to levers A and B, respectively. The short arm of A, which is worked from the piston of the cylinder Z, is connected by a link, c, to a sleeve, C, iirted between collars on the slide-rod D, which is tted with a feather` to slide through another sleeve, E. The sleeve E has on it a toothed bevel-segment, e, gearing with a segment, b, on B, which is worked from the piston of the cylinder 7c. Both the levers A and B are mounted on trunnions of a stationary bracket, F, within which the sleeve E is free to turn. Thus the lever A,moved by the one piston-that of the cylinder Z-gives, through the link c,to the slide-rod D a to-andfro reciprocating movement, and the lever B, moved by the other piston-that ofthe cylinder k, by means of the bevel-gear?) and c-gives the slide-rod D a partial rotation to and fro on its own axis. The slide-valve G has a face, which is a segment of a cylinder, with a central cavity tting to a cylindrical casing, in which there are formed iive ports-a central port, H, for exhaust; two end ports, K K', leading to the two ends ofthe cylinder k, and two side ports, L L', leading tothe two ends of the cylinder Z. The slide-valve G, as it is moved to and fro longitudinally by the piston of the one cylinder, Z, over the ports K K', governs the supply and exhaust of the other cylinder, k, and the same slide-valve G, as it is rocked to and fro transversely by the piston of the cylinder 7c over the ports L L', governs the supply and exhaust of the other cylinder, Z.

The slide-valve may be shaped and moved diagonally, as shown in Figs. 4, 5, and 6, the four ports K K' and L L' being arranged in diamond form, parallel, respectively, to the four sides of the slide-valve. The opening and closing of the ports being then effected by the movements of the slide-valve, cornpounded of its longitudinal and transverse motions, would recur in an order corresponding nearly to movements of the two pistons, such as they would have if they were connected to cranks at right angles to one another.

Other forms might be given to the slidevalve, the four ports around the central eX- haust-port being arranged and situated to suit the shape and the two motions of the slidevalve.

Having thus described the nature of my invention and the best means I know for carrying the same into practical effect, I claiml. In a duplex direct-acting pumping-engine, the combination of the two piston-rods, the two levers pivoted near their upper ends and connected with the piston-rods,the valverod carrying the slide-valve, a loose connection between the upper end of one of said levers and the valve-rod, a sleeve keyed to the valve-rod and provided with a gear, and a gear on the other lever engaging said gear on'the sleeve, for imparting longitudinalart transverse movements to the slide-valve, substantially as and for the purposes described.

2. In a duplex direct-acting pumping-enscrbing witnesses, this 8th day of September, 1o gine having a single slide-waive moved lon- A. D. 1885. 0fitudinally and transversely, the combina- T T t ion of the two piston-rods, the levers A B, JOHL FIDLDIB (L 5 the slide-valve rod D, the sleeve C and its Vitnesses:

link o, and the bevel-segments b and e, sub- G. G. BAKER, stnntinlly as described. 16 New Street, Gloucester.

In testimony whereof Ihzwesignedniyname R. F. SMART,

t0 this specification, in the presence of two sub- 19 Sebert Street, Gloucester. 

